This invention relates to a sheet discharge control method and a sheet discharge apparatus for stacking sheets formed thereupon with images discharged from an image forming apparatus such as a copier or printer.
Conventionally, a sheet discharge apparatus (or a so-called finisher) is used for stacking sheets formed thereupon with images by an image forming apparatus such as a copier or printer on a stacking tray. These types of sheet discharge apparatuses have a straight operating mode and a shift operating mode that performs later processes such as stapling the sheets or punching holes therein, according to the operating instructions on the image forming apparatus.
In the straight operating mode, sheets are discharged directly to the stacking tray passing through the transport path while in the shift operating mode, a plurality of sheets sequentially switched back to a processing tray along a transport path undergo subsequent processing such as stapling or hole punching after having been aligned by an aligning means, then are discharged to a stacking tray as a sheet bundle.
FIG. 22 illustrates the state of discharge of sheets formed with images in the conventional sheet discharge apparatus, FIG. 23 is a flowchart showing the processing procedures relating to the positioning control of a stacking tray on a conventional sheet discharge apparatus.
In FIG. 22 and FIG. 23, the sheet S is sent to the sheet discharge apparatus 11 from the image forming apparatus G such as a copier or printer. At the same time, a command specifying the binding mode is received from the image forming apparatus to the sheet discharge apparatus 11 thereby setting this mode. A paper surface detection lever, not shown in the drawings, protrudes to hold the sheet S with this operation setting. The position of the stacking tray 15 is determined after a set time has passed and is positioned (step S1). Also, if not already positioned at the predetermined home position, the stacking tray 15 is controlled to be elevated to the home position.
Firstly, if the stacking tray 15 is at its lowest position, a control is executed to raise it. When it is recognized at its home position, the raising of the stacking tray 15 is stopped (steps S2, S3 and S4.) If the stacking tray 15 is at its home position at step S1, the stacking tray 15 is not moved (step S5). Then, if the stacking tray 15 is at its highest position, a control is executed to lower it (step S6). When it is recognized to be at its home position, the lowering of the stacking tray 15 is stopped (steps S7 and S8.)
Thus sheets are discharged to the stacking tray 15 at the home position. In other words, sheets are discharged to their normal position in the stacking tray 15 at the home position. In such cases, if the stacking tray 15 is positioned lower than the home position, sheets will fall into the stacking tray 15, as shown in FIG. 22.
With this shift mode, a sheet is transported while a processing weight, not shown in the drawings, rotatably supported above the endless transport belt 28 presses against to touch the endless transport belt 28 to the sheet S, but the sheet S experiences curls (the edges of the sheet curl upward) caused by the image forming process in the image forming portion of the image forming apparatus G. Because the upstream edge of the sheet S curls upward, after the upstream edge of the sheet in the direction of transport passes the nipping region pressed to the endless transport belt by the aforementioned processing weight, there is less contact surfaces therebetween the sheet and caterpillar roller thus making it difficult to transmit the endless transport belt 28""s transport force to the sheet S, thus causing the problem of not fully switching back the sheet S in the processing tray 39.
Furthermore, as shown in FIG. 22, if the gap between the stacking tray 15 and processing tray 39 is large in the vertical direction, the sheet S will slip down into the stacking tray 15, the upstream edge of the sheet S in the transport direction being urged in a direction away from the endless transport belt 28. This makes it even more difficult to transmit the transport force from the endless transport belt 28 to the sheet S. Even if the sheet S were to be in contact with the sheet S, a bending would develop in the sheet S between the stacking tray 15 and the caterpillar roller thereby increasing the transport load and making it difficult for the sheet to be completely switch-back transported by the endless transport belt 28.
Note that when the second or subsequent sheet is transported, it passes over the first sheet and the transport is executed without error and such bending stops occurring.
To resolve the issues of the prior art, an object of the present invention is to provide a program for a sheet discharge control method and a sheet discharge control apparatus that can control the relative heights and angles of a stacking tray and to process according to the number of sheets discharged and to control the height and angle of the stacking tray when discharging sheets and when discharging sheet bundles to improve the alignment of discharged sheets and the characteristics of transport thereof.
To attain the aforementioned objectives, the sheet discharge apparatus according to the present invention is equipped with a discharge means for discharging sheets received from an image forming apparatus, a support means established downstream of the aforementioned discharge means in the direction of sheet discharge, a storage means established downstream of the aforementioned support means in the direction of sheet discharge, a transport means for transporting to the aforementioned storage means a sheet discharged by the aforementioned discharge means straddling the aforementioned support means and the aforementioned storage means, an elevator means for relatively raising or lowering the aforementioned support means and the aforementioned storage means and a control mean to control the aforementioned elevator means to vary the position of the aforementioned storage means to the aforementioned support means according to the number of sheets discharged by the aforementioned discharge means.
The sheet discharge apparatus according to the present invention has a control means for controlling the aforementioned elevator means so that the relative position of the aforementioned storage means is lower with regard to the aforementioned support means after a determined number of sheets are discharged by the aforementioned discharge means.
The sheet discharge apparatus according to the present invention has a control means for controlling the aforementioned elevator means so that the downstream edge in the direction of transport of a sheet discharged by the aforementioned discharge means is higher than the highest level of the aforementioned support means until a determined number of sheets are discharged by the aforementioned discharge means.
To attain the aforementioned objectives, the sheet discharge apparatus according to the present invention is equipped with a discharge means for discharging sheets received from an image forming apparatus, a support means established downstream of the aforementioned discharge means in the direction of sheet discharge, a storage means established downstream of the aforementioned support means in the, direction of sheet discharge, a transport means for transporting to the aforementioned storage means a sheet discharged by the aforementioned discharge means straddling the aforementioned support means and the aforementioned storage means, an inclining means for varying the relative angle of incline of the aforementioned support means and the aforementioned storage means and a control means to control the aforementioned inclining means so that the angle of incline of the aforementioned storage means to the aforementioned support means is different.
The sheet discharge apparatus according to the present invention has a control means for controlling the aforementioned inclining means so that the angle of incline of the aforementioned storage means is smaller with regard to the aforementioned support means after a determined number of sheets are discharged by the aforementioned discharge means.
The sheet discharge apparatus according to the present invention has a control means for controlling the aforementioned inclining means so that the downstream edge in the direction of transport of a sheet discharged by the aforementioned discharge means is higher than the highest level of the aforementioned support means until a determined number of sheets are discharged by the aforementioned discharge means.
To attain the aforementioned objectives, the sheet discharge apparatus according to the present invention is equipped with a discharge means for discharging sheets received from an image forming apparatus, a support means established downstream of the aforementioned discharge means in the direction of sheet discharge, a storage means established downstream of the aforementioned support means in the direction of sheet discharge, a transport means for transporting to the aforementioned storage means a discharged sheet by the aforementioned discharge means straddling the aforementioned support means and the aforementioned storage means, an elevator means for relatively raising or lowering the aforementioned support means and the aforementioned storage means, an inclining means for varying the relative angle of incline of the aforementioned support means and the aforementioned storage means and a control means for controlling the aforementioned elevator means so that the position of the aforementioned storage means to the aforementioned support means varies when discharging the sheet with the aforementioned discharge means and when transporting the sheet with the aforementioned transport means.
The sheet discharge apparatus according to the present invention has a control means for controlling the aforementioned elevator means so that the relative position of the aforementioned storage means is lower with regard to the aforementioned support means after a determined number of sheets are discharged by the aforementioned discharge means.
The sheet discharge apparatus according to the present invention has a control means for controlling the aforementioned elevator means so that the downstream edge in the direction of transport of a sheet discharged by the aforementioned discharge means is higher than the highest portion of the aforementioned support means when sheets are discharged by the aforementioned discharge means.
The sheet discharge apparatus according to the present invention is equipped with a discharge means for discharging sheets received from an image forming apparatus, a support means established downstream of the aforementioned discharge means in the direction of sheet discharge, a storage means established downstream of the aforementioned support means in the direction of sheet discharge, a transport means for transporting to the aforementioned storage means a discharged sheet by the aforementioned discharge means straddling the aforementioned support means and the aforementioned storage means, an elevator means for relatively raising or lowering the aforementioned support means and the aforementioned storage means, and a control means for controlling the aforementioned inclining means so that the angle of incline of the aforementioned storage means to the aforementioned support means is different when discharging the sheet with the aforementioned discharge means and when transporting the sheet with the aforementioned transport means.
The sheet discharge apparatus according to the present invention has a control means for controlling the aforementioned inclining means so that the angle of incline of the aforementioned storage means is smaller with regard to the aforementioned support means for the sheet transfer by the aforementioned transfer means that the discharge of sheets by the aforementioned discharge means.
The sheet discharge apparatus according to the present invention has a control means for controlling the aforementioned inclining means so that the downstream edge in the direction of transport of a sheet discharged by the aforementioned discharge means is higher than the highest portion of the aforementioned support means when sheets are discharged by the aforementioned discharge means.
The sheet discharge apparatus according to the present invention is further equipped with a finishing means that finishes sheets discharged by the aforementioned discharge means, while straddling the aforementioned support means and the aforementioned storage means
This structure controls the height and the incline of the stacking tray according to the number of sheets discharged and controls the height and the inclining of the stacking tray according to sheet discharge and to sheet bundle discharge. Therefore, it improves the alignment of discharged sheets and transporting characteristics.